package com.itheima.filter;

import com.alibaba.fastjson.JSON;
import com.itheima.common.R;
import com.itheima.utils.BaseContext;
import lombok.extern.slf4j.Slf4j;
import org.springframework.util.AntPathMatcher;

import javax.servlet.*;
import javax.servlet.annotation.WebFilter;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.IOException;

/**
 * @author Tang
 * @date 2023/4/11
 */
@Slf4j
//value和urlPatterns效果是一样的 /*代表拦截所有请求
@WebFilter(filterName = "loginCheckFilter",urlPatterns = "/*")
public class LoginCheckFilter implements Filter {


    String[] urls = new String[]{
            "/employee/login",
            "/employee/logout",
            "/backend/**",
            "/front/**",
            "/common/**",
            "/user/sendMsg",
            "/user/login",
            "/doc.html",
            "/webjars/**",
            "/swagger-resources",
            "/v2/api-docs"
    };
    //路径匹配器，支持通配符
    public static final AntPathMatcher PATH_MATCHER =new AntPathMatcher();

    @Override
    public void doFilter(ServletRequest servletRequest, ServletResponse servletResponse, FilterChain filterChain) throws IOException, ServletException {
        HttpServletRequest request =(HttpServletRequest) servletRequest;
        HttpServletResponse response =(HttpServletResponse) servletResponse;
        //1、获取本次请求的URI
        String requestURI =request.getRequestURI();

        log.info("拦截到请求：{}",requestURI);

        //定义不需要处理的请求路径

        boolean check = check(urls, requestURI);
        //2、判断本次请求是否需要处理 如果不需要处理，则直接放行
        if (check){
            log.info("本次请求{}不需要处理",requestURI);
            filterChain.doFilter(request, response);
            return;
        }

        //3、判断员工登录状态，如果已登录，则直接放行
        if (request.getSession().getAttribute("employee")!=null){
            log.info("用户已登录，用户id为:{}", request.getSession().getAttribute("employee"));
            //4、将当前登录的ID记录到ThreadLocal中
            BaseContext.setValue((Long)request.getSession().getAttribute("employee"));
            filterChain.doFilter(request,response);
            return;
        }
        //4、判断用户登录状态，如果已登录，则直接放行
        if(request.getSession().getAttribute("user")!=null){
            log.info("用户已登录，用户id为：{}",request.getSession().getAttribute("user"));
            Long user = (Long) request.getSession().getAttribute("user");
            BaseContext.setValue(user);
            filterChain.doFilter(request,response);
            return;
        }
        log.info("用户未登录");

        //5、如果未登录则返回未登录结果，通过输出流方式向客户端页面响应数据
        response.getWriter().write(JSON.toJSONString(R.error("NOTLOGIN")));
        return;
    }
    /**
     * 路径匹配，检查本次请求是否需要放行
     * @param urls
     * @param requestURI
     * @return
     */
    public boolean check(String[] urls,String requestURI){
        for (String url : urls) {
            boolean match = PATH_MATCHER.match(url, requestURI);
            if(match){
                return true;
            }
        }
        return false;
    }
}
